Lenses incorporated in cameras today have a fixed geometry, and can be either portrait lenses, standard lenses, wide-angle lenses, etc. Various scenes, however, call for various types of lenses. For example, a photographer taking a portrait picture, would not want to use a wide-angle lens, or a photographer taking a landscape picture would not want to use a portrait lens. As a result, photographers carry various bulky lenses to attach to a camera body. If a wide-angle lenses is mounted on the camera body, and the photographer wants to take a portrait picture, the photographer must remove the wide-angle lens, and mount the portrait lens on the camera body.